1. Field of the Invention
The present invention is related to a light emitting diode (LED) chip package and the method of making the same, and more particularly, to an LED chip package utilizing a semiconductor substrate as a package substrate and able to fulfill electrical connection of a plurality of LEDs in series or in parallel easily and a wafer level packaging method of LED chip.
2. Description of the Prior Art
There are mainly two kinds of conventional Surface Mount Device (SMD) LED packaging methods: one of which utilizes a leadframe made of metal materials as a package substrate and the LED chip is mounted on the leadframe; the other method utilizes a printed circuit board (PCB) as a package substrate and the LED chip is mounted on the PCB.
FIG. 1 is a schematic view of a conventional LED chip package utilizing leadframe as a package substrate. As shown in FIG. 1, the conventional LED chip package 1 includes a base 2 formed by injection molding technique, and a leadframe 3 immobilized on the base 2 to form a package substrate 4. The LED chip 5 is mounted on the leadframe 3, and encapsulated on the package substrate 4 with package resin 6. One of the electrodes of LED chip 5 is directly electrically connected to the leadframe 3 located on one side of the package substrate 4, while another electrode is electrically connected to the leadframe 3 on the other side of the package substrate 4 via bonding wire 7 by wire bonding technique.
FIG. 2 is a schematic view of another conventional LED chip package utilizing PCB as a package substrate. As shown in FIG. 2, the conventional LED chip package 10 utilizes PCB 11, made of plastic, as a base, and wires 12 made of copper are laid on the PCB 11. The LED chip 13 is mounted on the PCB 11 and encapsulated with package resin 14, wherein one of the electrodes of the LED chip 13 is directly electrically connected to the wire 12 on one side of the PCB 11, and the other electrode is electrically connected to the wire 12 on the other side of the PCB 11 via the bonding wire 15 by wire bonding technique.
However both of the above mentioned conventional LED chip packages share common shortcomings listed as follows. First, the heat dissipation efficiency of conventional LED chip package is low. Whether the LED chip package is a leadframe type or a PCB type, the package substrate and the package resin are poor heat dissipation materials such as plastic or resin, and heat produced while light is emitted by the LED chips may not be quickly and efficiently dissipated. The accumulated heat would lead to increased temperature of the LED chip and therefore influence the illumination efficiency and life span of the LED chip. In addition, the conventional LED chip package utilizes bonding wire formed by the wire bonding technique to implement external electrical connection of the LED chip. However, the bonding wire itself must have a certain arch that has a height higher than the LED chip; hence the fabrication of the lens to be formed would be difficult.